What causes flooding in urban areas ?
Urban areas are highly impermeable, there are very few areas within UK towns and cities that allow rainwater to infiltrate naturally into the ground, these parks and gardens will allow the water to pass naturally into the ground and back to the water table. Unfortunately the impermeable areas lead to high amounts of storm water runoff when rainfall occurs and this causes localized flooding, such as ponding on pavements and roads as illustrated by this picture of a front driveway. It can also cause flooding of the receiving water bodies after the rainwater passes through the drainage network and into the rivers.
